f01c443f2a
Slab and pool side walls assumed a CCW contour (the unflipped quad's right-hand normal is outward only for CCW), but outsetPolygon and the slab tool preserve the drawn winding. A CW-drawn slab therefore got inward-facing side-wall normals that FrontSide culling dropped, so the slab read as see-through from the camera-facing side (~half the time, depending on draw direction). Normalize the contour to CCW (reverse when signed area < 0) before building both the positive-slab and pool geometry. Caps are unaffected (Earcut normalizes the outer ring); holes are already double-emitted + winding-normalized; ceilings use flat ShapeGeometry (no extruded walls); autoFromWalls slabs are already CCW so this is a no-op for them. Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>